'\" e
'\"! eqn | mmdoc
'\"macro stdmacro
.ds Vn Version 1.2
.ds Dt 24 September 1999
.ds Re Release 1.2.1
.ds Dp Jan 14 18:30
.ds Dm 01 gettexenv
.ds Xs 32087 4 gettexenv.gl
.TH GLGETTEXENV 3G
.SH NAME
.B "glGetTexEnvfv, glGetTexEnviv
\- return texture environment parameters

.SH C SPECIFICATION
void \f3glGetTexEnvfv\fP(
GLenum \fItarget\fP,
.nf
.ta \w'\f3void \fPglGetTexEnvfv( 'u
	GLenum \fIpname\fP,
	GLfloat \fI*params\fP )
.fi
void \f3glGetTexEnviv\fP(
GLenum \fItarget\fP,
.nf
.ta \w'\f3void \fPglGetTexEnviv( 'u
	GLenum \fIpname\fP,
	GLint \fI*params\fP )
.fi

.SH PARAMETERS
.TP \w'\f2target\fP\ \ 'u 
\f2target\fP
Specifies a texture environment.
Must be \%\f3GL_TEXTURE_ENV\fP.
.TP
\f2pname\fP
Specifies the symbolic name of a texture environment parameter.
Accepted values are \%\f3GL_TEXTURE_ENV_MODE\fP and \%\f3GL_TEXTURE_ENV_COLOR\fP.
.TP
\f2params\fP
Returns the requested data.
.SH DESCRIPTION
\%\f3glGetTexEnv\fP returns in \f2params\fP selected values of a texture environment that
was specified with \%\f3glTexEnv\fP.
\f2target\fP specifies a texture environment.
Currently, only one texture environment is defined and supported:
\%\f3GL_TEXTURE_ENV\fP. 
.P
\f2pname\fP names a specific texture environment parameter, as follows:
.TP 10
\%\f3GL_TEXTURE_ENV_MODE\fP
\f2params\fP returns the single-valued texture environment mode,
a symbolic constant. The initial value is \%\f3GL_MODULATE\fP.
.TP
\%\f3GL_TEXTURE_ENV_COLOR\fP
\f2params\fP returns four integer or floating-point values that are the
texture environment color.  
Integer values,
when requested,
are linearly mapped from the internal floating-point representation
such that 1.0 maps to the most positive representable integer,
and \-1.0 maps to the most negative representable integer. The initial
value is (0, 0, 0, 0).
.SH NOTES
If an error is generated,
no change is made to the contents of \f2params\fP.
.P
When the \%\f3GL_ARB_multitexture\fP extension is supported, \%\f3glGetTexEnv\fP returns
the texture environment parameters for the active texture unit.
.SH ERRORS
\%\f3GL_INVALID_ENUM\fP is generated if \f2target\fP or \f2pname\fP is not an
accepted value.
.P
\%\f3GL_INVALID_OPERATION\fP is generated if \%\f3glGetTexEnv\fP
is executed between the execution of \%\f3glBegin\fP
and the corresponding execution of \%\f3glEnd\fP.
.SH SEE ALSO
\%\f3glActiveTextureARB(3G)\fP,
\%\f3glTexEnv(3G)\fP
